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580e7e8eb9
minetest/src/pathfinder.cpp
Wuzzy 580e7e8eb9 Fix pathfinder bugs: returning nil frequently, broken A*, jump through solid nodes (#9339) 
* Fix pathfinder fail when startpos is over air
* Note down pathfinder restrictions
* Implement real A* search
* Pathfinder: Implement buildPath non-recursively
* Update find_path documentation
* Pathfinder: Check if jump path is unobstructed
* Pathfinder: Fix drop check first checking upwards
* Pathfinder: Return nil if source or dest are solid
* Pathfinder: Use priority queue for open list
2020-03-05 12:09:44 +01:00

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/*
Minetest
Copyright (C) 2013 sapier, sapier at gmx dot net
Copyright (C) 2016 est31, <MTest31@outlook.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/******************************************************************************/
/* Includes */
/******************************************************************************/
#include "pathfinder.h"
#include "serverenvironment.h"
#include "server.h"
#include "nodedef.h"
//#define PATHFINDER_DEBUG
//#define PATHFINDER_CALC_TIME
#ifdef PATHFINDER_DEBUG
#include <string>
#endif
#ifdef PATHFINDER_DEBUG
#include <iomanip>
#endif
#ifdef PATHFINDER_CALC_TIME
#include <sys/time.h>
#endif
/******************************************************************************/
/* Typedefs and macros */
/******************************************************************************/
#define LVL "(" << level << ")" <<
#ifdef PATHFINDER_DEBUG
#define DEBUG_OUT(a) std::cout << a
#define INFO_TARGET std::cout
#define VERBOSE_TARGET std::cout
#define ERROR_TARGET std::cout
#else
#define DEBUG_OUT(a) while(0)
#define INFO_TARGET infostream << "Pathfinder: "
#define VERBOSE_TARGET verbosestream << "Pathfinder: "
#define ERROR_TARGET warningstream << "Pathfinder: "
#endif
#define PATHFINDER_MAX_WAYPOINTS 700
/******************************************************************************/
/* Class definitions */
/******************************************************************************/
/** representation of cost in specific direction */
class PathCost {
public:
/** default constructor */
PathCost() = default;
/** copy constructor */
PathCost(const PathCost &b);
/** assignment operator */
PathCost &operator= (const PathCost &b);
bool valid = false; /**< movement is possible */
int value = 0; /**< cost of movement */
int y_change = 0; /**< change of y position of movement */
bool updated = false; /**< this cost has ben calculated */
};
/** representation of a mapnode to be used for pathfinding */
class PathGridnode {
public:
/** default constructor */
PathGridnode() = default;
/** copy constructor */
PathGridnode(const PathGridnode &b);
/**
* assignment operator
* @param b node to copy
*/
PathGridnode &operator= (const PathGridnode &b);
/**
* read cost in a specific direction
* @param dir direction of cost to fetch
*/
PathCost getCost(v3s16 dir);
/**
* set cost value for movement
* @param dir direction to set cost for
* @cost cost to set
*/
void setCost(v3s16 dir, const PathCost &cost);
bool valid = false; /**< node is on surface */
bool target = false; /**< node is target position */
bool source = false; /**< node is stating position */
int totalcost = -1; /**< cost to move here from starting point */
int estimated_cost = -1; /**< totalcost + heuristic cost to end */
v3s16 sourcedir; /**< origin of movement for current cost */
v3s16 pos; /**< real position of node */
PathCost directions[4]; /**< cost in different directions */
bool is_closed = false; /**< for A* search: if true, is in closed list */
bool is_open = false; /**< for A* search: if true, is in open list */
/* debug values */
bool is_element = false; /**< node is element of path detected */
char type = 'u'; /**< Type of pathfinding node.
* u = unknown
* i = invalid
* s = surface (walkable node)
* - = non-walkable node (e.g. air) above surface
* g = other non-walkable node
*/
};
class Pathfinder;
class PathfinderCompareHeuristic;
/** Abstract class to manage the map data */
class GridNodeContainer {
public:
virtual PathGridnode &access(v3s16 p)=0;
virtual ~GridNodeContainer() = default;
protected:
Pathfinder *m_pathf;
void initNode(v3s16 ipos, PathGridnode *p_node);
};
class ArrayGridNodeContainer : public GridNodeContainer {
public:
virtual ~ArrayGridNodeContainer() = default;
ArrayGridNodeContainer(Pathfinder *pathf, v3s16 dimensions);
virtual PathGridnode &access(v3s16 p);
private:
v3s16 m_dimensions;
int m_x_stride;
int m_y_stride;
std::vector<PathGridnode> m_nodes_array;
};
class MapGridNodeContainer : public GridNodeContainer {
public:
virtual ~MapGridNodeContainer() = default;
MapGridNodeContainer(Pathfinder *pathf);
virtual PathGridnode &access(v3s16 p);
private:
std::map<v3s16, PathGridnode> m_nodes;
};
/** class doing pathfinding */
class Pathfinder {
public:
/**
* default constructor
*/
Pathfinder() = default;
~Pathfinder();
/**
* path evaluation function
* @param env environment to look for path
* @param source origin of path
* @param destination end position of path
* @param searchdistance maximum number of nodes to look in each direction
* @param max_jump maximum number of blocks a path may jump up
* @param max_drop maximum number of blocks a path may drop
* @param algo Algorithm to use for finding a path
*/
std::vector<v3s16> getPath(ServerEnvironment *env,
v3s16 source,
v3s16 destination,
unsigned int searchdistance,
unsigned int max_jump,
unsigned int max_drop,
PathAlgorithm algo);
private:
/* helper functions */
/**
* transform index pos to mappos
* @param ipos a index position
* @return map position
*/
v3s16 getRealPos(v3s16 ipos);
/**
* transform mappos to index pos
* @param pos a real pos
* @return index position
*/
v3s16 getIndexPos(v3s16 pos);
/**
* get gridnode at a specific index position
* @param ipos index position
* @return gridnode for index
*/
PathGridnode &getIndexElement(v3s16 ipos);
/**
* Get gridnode at a specific index position
* @return gridnode for index
*/
PathGridnode &getIdxElem(s16 x, s16 y, s16 z);
/**
* invert a 3D position (change sign of coordinates)
* @param pos 3D position
* @return pos *-1
*/
v3s16 invert(v3s16 pos);
/**
* check if a index is within current search area
* @param index position to validate
* @return true/false
*/
bool isValidIndex(v3s16 index);
/* algorithm functions */
/**
* calculate 2D Manhattan distance to target
* @param pos position to calc distance
* @return integer distance
*/
int getXZManhattanDist(v3s16 pos);
/**
* calculate cost of movement
* @param pos real world position to start movement
* @param dir direction to move to
* @return cost information
*/
PathCost calcCost(v3s16 pos, v3s16 dir);
/**
* recursive update whole search areas total cost information
* @param ipos position to check next
* @param srcdir positionc checked last time
* @param total_cost cost of moving to ipos
* @param level current recursion depth
* @return true/false path to destination has been found
*/
bool updateAllCosts(v3s16 ipos, v3s16 srcdir, int current_cost, int level);
/**
* try to find a path to destination using a heuristic function
* to estimate distance to target (A* search algorithm)
* @param isource start position (index pos)
* @param idestination end position (index pos)
* @return true/false path to destination has been found
*/
bool updateCostHeuristic(v3s16 isource, v3s16 idestination);
/**
* build a vector containing all nodes from destination to source;
* to be called after the node costs have been processed
* @param path vector to add nodes to
* @param ipos initial pos to check (index pos)
* @return true/false path has been fully built
*/
bool buildPath(std::vector<v3s16> &path, v3s16 ipos);
/**
* go downwards from a position until some barrier
* is hit.
* @param pos position from which to go downwards
* @param max_down maximum distance to go downwards
* @return new position after movement; if too far down,
* pos is returned
*/
v3s16 walkDownwards(v3s16 pos, unsigned int max_down);
/* variables */
int m_max_index_x = 0; /**< max index of search area in x direction */
int m_max_index_y = 0; /**< max index of search area in y direction */
int m_max_index_z = 0; /**< max index of search area in z direction */
int m_searchdistance = 0; /**< max distance to search in each direction */
int m_maxdrop = 0; /**< maximum number of blocks a path may drop */
int m_maxjump = 0; /**< maximum number of blocks a path may jump */
int m_min_target_distance = 0; /**< current smalest path to target */
bool m_prefetch = true; /**< prefetch cost data */
v3s16 m_start; /**< source position */
v3s16 m_destination; /**< destination position */
core::aabbox3d<s16> m_limits; /**< position limits in real map coordinates */
/** contains all map data already collected and analyzed.
Access it via the getIndexElement/getIdxElem methods. */
friend class GridNodeContainer;
GridNodeContainer *m_nodes_container = nullptr;
ServerEnvironment *m_env = 0; /**< minetest environment pointer */
friend class PathfinderCompareHeuristic;
#ifdef PATHFINDER_DEBUG
/**
* print collected cost information
*/
void printCost();
/**
* print collected cost information in a specific direction
* @param dir direction to print
*/
void printCost(PathDirections dir);
/**
* print type of node as evaluated
*/
void printType();
/**
* print pathlenght for all nodes in search area
*/
void printPathLen();
/**
* print a path
* @param path path to show
*/
void printPath(std::vector<v3s16> path);
/**
* print y direction for all movements
*/
void printYdir();
/**
* print y direction for moving in a specific direction
* @param dir direction to show data
*/
void printYdir(PathDirections dir);
/**
* helper function to translate a direction to speaking text
* @param dir direction to translate
* @return textual name of direction
*/
std::string dirToName(PathDirections dir);
#endif
};
/** Helper class for the open list priority queue in the A* pathfinder
* to sort the pathfinder nodes by cost.
*/
class PathfinderCompareHeuristic
{
private:
Pathfinder *myPathfinder;
public:
PathfinderCompareHeuristic(Pathfinder *pf)
{
myPathfinder = pf;
}
bool operator() (v3s16 pos1, v3s16 pos2) {
v3s16 ipos1 = myPathfinder->getIndexPos(pos1);
v3s16 ipos2 = myPathfinder->getIndexPos(pos2);
PathGridnode &g_pos1 = myPathfinder->getIndexElement(ipos1);
PathGridnode &g_pos2 = myPathfinder->getIndexElement(ipos2);
if (!g_pos1.valid)
return false;
if (!g_pos2.valid)
return false;
return g_pos1.estimated_cost > g_pos2.estimated_cost;
}
};
/******************************************************************************/
/* implementation */
/******************************************************************************/
std::vector<v3s16> get_path(ServerEnvironment* env,
v3s16 source,
v3s16 destination,
unsigned int searchdistance,
unsigned int max_jump,
unsigned int max_drop,
PathAlgorithm algo)
{
Pathfinder searchclass;
return searchclass.getPath(env,
source, destination,
searchdistance, max_jump, max_drop, algo);
}
/******************************************************************************/
PathCost::PathCost(const PathCost &b)
{
valid = b.valid;
y_change = b.y_change;
value = b.value;
updated = b.updated;
}
/******************************************************************************/
PathCost &PathCost::operator= (const PathCost &b)
{
valid = b.valid;
y_change = b.y_change;
value = b.value;
updated = b.updated;
return *this;
}
/******************************************************************************/
PathGridnode::PathGridnode(const PathGridnode &b)
: valid(b.valid),
target(b.target),
source(b.source),
totalcost(b.totalcost),
sourcedir(b.sourcedir),
pos(b.pos),
is_element(b.is_element),
type(b.type)
{
directions[DIR_XP] = b.directions[DIR_XP];
directions[DIR_XM] = b.directions[DIR_XM];
directions[DIR_ZP] = b.directions[DIR_ZP];
directions[DIR_ZM] = b.directions[DIR_ZM];
}
/******************************************************************************/
PathGridnode &PathGridnode::operator= (const PathGridnode &b)
{
valid = b.valid;
target = b.target;
source = b.source;
is_element = b.is_element;
totalcost = b.totalcost;
sourcedir = b.sourcedir;
pos = b.pos;
type = b.type;
directions[DIR_XP] = b.directions[DIR_XP];
directions[DIR_XM] = b.directions[DIR_XM];
directions[DIR_ZP] = b.directions[DIR_ZP];
directions[DIR_ZM] = b.directions[DIR_ZM];
return *this;
}
/******************************************************************************/
PathCost PathGridnode::getCost(v3s16 dir)
{
if (dir.X > 0) {
return directions[DIR_XP];
}
if (dir.X < 0) {
return directions[DIR_XM];
}
if (dir.Z > 0) {
return directions[DIR_ZP];
}
if (dir.Z < 0) {
return directions[DIR_ZM];
}
PathCost retval;
return retval;
}
/******************************************************************************/
void PathGridnode::setCost(v3s16 dir, const PathCost &cost)
{
if (dir.X > 0) {
directions[DIR_XP] = cost;
}
if (dir.X < 0) {
directions[DIR_XM] = cost;
}
if (dir.Z > 0) {
directions[DIR_ZP] = cost;
}
if (dir.Z < 0) {
directions[DIR_ZM] = cost;
}
}
void GridNodeContainer::initNode(v3s16 ipos, PathGridnode *p_node)
{
const NodeDefManager *ndef = m_pathf->m_env->getGameDef()->ndef();
PathGridnode &elem = *p_node;
v3s16 realpos = m_pathf->getRealPos(ipos);
MapNode current = m_pathf->m_env->getMap().getNode(realpos);
MapNode below = m_pathf->m_env->getMap().getNode(realpos + v3s16(0, -1, 0));
if ((current.param0 == CONTENT_IGNORE) ||
(below.param0 == CONTENT_IGNORE)) {
DEBUG_OUT("Pathfinder: " << PP(realpos) <<
" current or below is invalid element" << std::endl);
if (current.param0 == CONTENT_IGNORE) {
elem.type = 'i';
DEBUG_OUT(PP(ipos) << ": " << 'i' << std::endl);
}
return;
}
//don't add anything if it isn't an air node
if (ndef->get(current).walkable || !ndef->get(below).walkable) {
DEBUG_OUT("Pathfinder: " << PP(realpos)
<< " not on surface" << std::endl);
if (ndef->get(current).walkable) {
elem.type = 's';
DEBUG_OUT(PP(ipos) << ": " << 's' << std::endl);
} else {
elem.type = '-';
DEBUG_OUT(PP(ipos) << ": " << '-' << std::endl);
}
return;
}
elem.valid = true;
elem.pos = realpos;
elem.type = 'g';
DEBUG_OUT(PP(ipos) << ": " << 'a' << std::endl);
if (m_pathf->m_prefetch) {
elem.directions[DIR_XP] = m_pathf->calcCost(realpos, v3s16( 1, 0, 0));
elem.directions[DIR_XM] = m_pathf->calcCost(realpos, v3s16(-1, 0, 0));
elem.directions[DIR_ZP] = m_pathf->calcCost(realpos, v3s16( 0, 0, 1));
elem.directions[DIR_ZM] = m_pathf->calcCost(realpos, v3s16( 0, 0,-1));
}
}
ArrayGridNodeContainer::ArrayGridNodeContainer(Pathfinder *pathf, v3s16 dimensions) :
m_x_stride(dimensions.Y * dimensions.Z),
m_y_stride(dimensions.Z)
{
m_pathf = pathf;
m_nodes_array.resize(dimensions.X * dimensions.Y * dimensions.Z);
INFO_TARGET << "Pathfinder ArrayGridNodeContainer constructor." << std::endl;
for (int x = 0; x < dimensions.X; x++) {
for (int y = 0; y < dimensions.Y; y++) {
for (int z= 0; z < dimensions.Z; z++) {
v3s16 ipos(x, y, z);
initNode(ipos, &access(ipos));
}
}
}
}
PathGridnode &ArrayGridNodeContainer::access(v3s16 p)
{
return m_nodes_array[p.X * m_x_stride + p.Y * m_y_stride + p.Z];
}
MapGridNodeContainer::MapGridNodeContainer(Pathfinder *pathf)
{
m_pathf = pathf;
}
PathGridnode &MapGridNodeContainer::access(v3s16 p)
{
std::map<v3s16, PathGridnode>::iterator it = m_nodes.find(p);
if (it != m_nodes.end()) {
return it->second;
}
PathGridnode &n = m_nodes[p];
initNode(p, &n);
return n;
}
/******************************************************************************/
std::vector<v3s16> Pathfinder::getPath(ServerEnvironment *env,
v3s16 source,
v3s16 destination,
unsigned int searchdistance,
unsigned int max_jump,
unsigned int max_drop,
PathAlgorithm algo)
{
#ifdef PATHFINDER_CALC_TIME
timespec ts;
clock_gettime(CLOCK_REALTIME, &ts);
#endif
std::vector<v3s16> retval;
//check parameters
if (env == 0) {
ERROR_TARGET << "Missing environment pointer" << std::endl;
return retval;
}
//initialization
m_searchdistance = searchdistance;
m_env = env;
m_maxjump = max_jump;
m_maxdrop = max_drop;
m_start = source;
m_destination = destination;
m_min_target_distance = -1;
m_prefetch = true;
if (algo == PA_PLAIN_NP) {
m_prefetch = false;
}
//calculate boundaries within we're allowed to search
int min_x = MYMIN(source.X, destination.X);
int max_x = MYMAX(source.X, destination.X);
int min_y = MYMIN(source.Y, destination.Y);
int max_y = MYMAX(source.Y, destination.Y);
int min_z = MYMIN(source.Z, destination.Z);
int max_z = MYMAX(source.Z, destination.Z);
m_limits.MinEdge.X = min_x - searchdistance;
m_limits.MinEdge.Y = min_y - searchdistance;
m_limits.MinEdge.Z = min_z - searchdistance;
m_limits.MaxEdge.X = max_x + searchdistance;
m_limits.MaxEdge.Y = max_y + searchdistance;
m_limits.MaxEdge.Z = max_z + searchdistance;
v3s16 diff = m_limits.MaxEdge - m_limits.MinEdge;
m_max_index_x = diff.X;
m_max_index_y = diff.Y;
m_max_index_z = diff.Z;
delete m_nodes_container;
if (diff.getLength() > 5) {
m_nodes_container = new MapGridNodeContainer(this);
} else {
m_nodes_container = new ArrayGridNodeContainer(this, diff);
}
#ifdef PATHFINDER_DEBUG
printType();
printCost();
printYdir();
#endif
//fail if source or destination is walkable
const NodeDefManager *ndef = m_env->getGameDef()->ndef();
MapNode node_at_pos = m_env->getMap().getNode(destination);
if (ndef->get(node_at_pos).walkable) {
VERBOSE_TARGET << "Destination is walkable. " <<
"Pos: " << PP(destination) << std::endl;
return retval;
}
node_at_pos = m_env->getMap().getNode(source);
if (ndef->get(node_at_pos).walkable) {
VERBOSE_TARGET << "Source is walkable. " <<
"Pos: " << PP(source) << std::endl;
return retval;
}
//If source pos is hovering above air, drop
//to the first walkable node (up to m_maxdrop).
//All algorithms expect the source pos to be *directly* above
//a walkable node.
v3s16 true_source = v3s16(source);
source = walkDownwards(source, m_maxdrop);
//If destination pos is hovering above air, go downwards
//to the first walkable node (up to m_maxjump).
//This means a hovering destination pos could be reached
//by a final upwards jump.
v3s16 true_destination = v3s16(destination);
destination = walkDownwards(destination, m_maxjump);
//validate and mark start and end pos
v3s16 StartIndex = getIndexPos(source);
v3s16 EndIndex = getIndexPos(destination);
PathGridnode &startpos = getIndexElement(StartIndex);
PathGridnode &endpos = getIndexElement(EndIndex);
if (!startpos.valid) {
VERBOSE_TARGET << "Invalid startpos " <<
"Index: " << PP(StartIndex) <<
"Realpos: " << PP(getRealPos(StartIndex)) << std::endl;
return retval;
}
if (!endpos.valid) {
VERBOSE_TARGET << "Invalid stoppos " <<
"Index: " << PP(EndIndex) <<
"Realpos: " << PP(getRealPos(EndIndex)) << std::endl;
return retval;
}
endpos.target = true;
startpos.source = true;
startpos.totalcost = 0;
bool update_cost_retval = false;
//calculate node costs
switch (algo) {
case PA_DIJKSTRA:
update_cost_retval = updateAllCosts(StartIndex, v3s16(0, 0, 0), 0, 0);
break;
case PA_PLAIN_NP:
case PA_PLAIN:
update_cost_retval = updateCostHeuristic(StartIndex, EndIndex);
break;
default:
ERROR_TARGET << "Missing PathAlgorithm" << std::endl;
break;
}
if (update_cost_retval) {
#ifdef PATHFINDER_DEBUG
std::cout << "Path to target found!" << std::endl;
printPathLen();
#endif
//find path
std::vector<v3s16> index_path;
buildPath(index_path, EndIndex);
//Now we have a path of index positions,
//and it's in reverse.
//The "true" start or end position might be missing
//since those have been given special treatment.
#ifdef PATHFINDER_DEBUG
std::cout << "Index path:" << std::endl;
printPath(index_path);
#endif
//from here we'll make the final changes to the path
std::vector<v3s16> full_path;
//calculate required size
int full_path_size = index_path.size();
if (source != true_source) {
full_path_size++;
}
if (destination != true_destination) {
full_path_size++;
}
full_path.reserve(full_path_size);
//manually add true_source to start of path, if needed
if (source != true_source) {
full_path.push_back(true_source);
}
//convert all index positions to "normal" positions and insert
//them into full_path in reverse
std::vector<v3s16>::reverse_iterator rit = index_path.rbegin();
for (; rit != index_path.rend(); ++rit) {
full_path.push_back(getIndexElement(*rit).pos);
}
//manually add true_destination to end of path, if needed
if (destination != true_destination) {
full_path.push_back(true_destination);
}
//Done! We now have a complete path of normal positions.
#ifdef PATHFINDER_DEBUG
std::cout << "Full path:" << std::endl;
printPath(full_path);
#endif
#ifdef PATHFINDER_CALC_TIME
timespec ts2;
clock_gettime(CLOCK_REALTIME, &ts2);
int ms = (ts2.tv_nsec - ts.tv_nsec)/(1000*1000);
int us = ((ts2.tv_nsec - ts.tv_nsec) - (ms*1000*1000))/1000;
int ns = ((ts2.tv_nsec - ts.tv_nsec) - ( (ms*1000*1000) + (us*1000)));
std::cout << "Calculating path took: " << (ts2.tv_sec - ts.tv_sec) <<
"s " << ms << "ms " << us << "us " << ns << "ns " << std::endl;
#endif
return full_path;
}
else {
#ifdef PATHFINDER_DEBUG
printPathLen();
#endif
INFO_TARGET << "No path found" << std::endl;
}
//return
return retval;
}
Pathfinder::~Pathfinder()
{
delete m_nodes_container;
}
/******************************************************************************/
v3s16 Pathfinder::getRealPos(v3s16 ipos)
{
return m_limits.MinEdge + ipos;
}
/******************************************************************************/
PathCost Pathfinder::calcCost(v3s16 pos, v3s16 dir)
{
const NodeDefManager *ndef = m_env->getGameDef()->ndef();
PathCost retval;
retval.updated = true;
v3s16 pos2 = pos + dir;
//check limits
if (!m_limits.isPointInside(pos2)) {
DEBUG_OUT("Pathfinder: " << PP(pos2) <<
" no cost -> out of limits" << std::endl);
return retval;
}
MapNode node_at_pos2 = m_env->getMap().getNode(pos2);
//did we get information about node?
if (node_at_pos2.param0 == CONTENT_IGNORE ) {
VERBOSE_TARGET << "Pathfinder: (1) area at pos: "
<< PP(pos2) << " not loaded";
return retval;
}
if (!ndef->get(node_at_pos2).walkable) {
MapNode node_below_pos2 =
m_env->getMap().getNode(pos2 + v3s16(0, -1, 0));
//did we get information about node?
if (node_below_pos2.param0 == CONTENT_IGNORE ) {
VERBOSE_TARGET << "Pathfinder: (2) area at pos: "
<< PP((pos2 + v3s16(0, -1, 0))) << " not loaded";
return retval;
}
//test if the same-height neighbor is suitable
if (ndef->get(node_below_pos2).walkable) {
//SUCCESS!
retval.valid = true;
retval.value = 1;
retval.y_change = 0;
DEBUG_OUT("Pathfinder: "<< PP(pos)
<< " cost same height found" << std::endl);
}
else {
//test if we can fall a couple of nodes (m_maxdrop)
v3s16 testpos = pos2 + v3s16(0, -1, 0);
MapNode node_at_pos = m_env->getMap().getNode(testpos);
while ((node_at_pos.param0 != CONTENT_IGNORE) &&
(!ndef->get(node_at_pos).walkable) &&
(testpos.Y > m_limits.MinEdge.Y)) {
testpos += v3s16(0, -1, 0);
node_at_pos = m_env->getMap().getNode(testpos);
}
//did we find surface?
if ((testpos.Y >= m_limits.MinEdge.Y) &&
(node_at_pos.param0 != CONTENT_IGNORE) &&
(ndef->get(node_at_pos).walkable)) {
if ((pos2.Y - testpos.Y - 1) <= m_maxdrop) {
//SUCCESS!
retval.valid = true;
retval.value = 2;
//difference of y-pos +1 (target node is ABOVE solid node)
retval.y_change = ((testpos.Y - pos2.Y) +1);
DEBUG_OUT("Pathfinder cost below height found" << std::endl);
}
else {
INFO_TARGET << "Pathfinder:"
" distance to surface below too big: "
<< (testpos.Y - pos2.Y) << " max: " << m_maxdrop
<< std::endl;
}
}
else {
DEBUG_OUT("Pathfinder: no surface below found" << std::endl);
}
}
}
else {
//test if we can jump upwards (m_maxjump)
v3s16 targetpos = pos2; // position for jump target
v3s16 jumppos = pos; // position for checking if jumping space is free
MapNode node_target = m_env->getMap().getNode(targetpos);
MapNode node_jump = m_env->getMap().getNode(jumppos);
bool headbanger = false; // true if anything blocks jumppath
while ((node_target.param0 != CONTENT_IGNORE) &&
(ndef->get(node_target).walkable) &&
(targetpos.Y < m_limits.MaxEdge.Y)) {
//if the jump would hit any solid node, discard
if ((node_jump.param0 == CONTENT_IGNORE) ||
(ndef->get(node_jump).walkable)) {
headbanger = true;
break;
}
targetpos += v3s16(0, 1, 0);
jumppos += v3s16(0, 1, 0);
node_target = m_env->getMap().getNode(targetpos);
node_jump = m_env->getMap().getNode(jumppos);
}
//check headbanger one last time
if ((node_jump.param0 == CONTENT_IGNORE) ||
(ndef->get(node_jump).walkable)) {
headbanger = true;
}
//did we find surface without banging our head?
if ((!headbanger) && (targetpos.Y <= m_limits.MaxEdge.Y) &&
(!ndef->get(node_target).walkable)) {
if (targetpos.Y - pos2.Y <= m_maxjump) {
//SUCCESS!
retval.valid = true;
retval.value = 2;
retval.y_change = (targetpos.Y - pos2.Y);
DEBUG_OUT("Pathfinder cost above found" << std::endl);
}
else {
DEBUG_OUT("Pathfinder: distance to surface above too big: "
<< (targetpos.Y - pos2.Y) << " max: " << m_maxjump
<< std::endl);
}
}
else {
DEBUG_OUT("Pathfinder: no surface above found" << std::endl);
}
}
return retval;
}
/******************************************************************************/
v3s16 Pathfinder::getIndexPos(v3s16 pos)
{
return pos - m_limits.MinEdge;
}
/******************************************************************************/
PathGridnode &Pathfinder::getIndexElement(v3s16 ipos)
{
return m_nodes_container->access(ipos);
}
/******************************************************************************/
inline PathGridnode &Pathfinder::getIdxElem(s16 x, s16 y, s16 z)
{
return m_nodes_container->access(v3s16(x,y,z));
}
/******************************************************************************/
bool Pathfinder::isValidIndex(v3s16 index)
{
if ( (index.X < m_max_index_x) &&
(index.Y < m_max_index_y) &&
(index.Z < m_max_index_z) &&
(index.X >= 0) &&
(index.Y >= 0) &&
(index.Z >= 0))
return true;
return false;
}
/******************************************************************************/
v3s16 Pathfinder::invert(v3s16 pos)
{
v3s16 retval = pos;
retval.X *=-1;
retval.Y *=-1;
retval.Z *=-1;
return retval;
}
/******************************************************************************/
bool Pathfinder::updateAllCosts(v3s16 ipos,
v3s16 srcdir,
int current_cost,
int level)
{
PathGridnode &g_pos = getIndexElement(ipos);
g_pos.totalcost = current_cost;
g_pos.sourcedir = srcdir;
level ++;
//check if target has been found
if (g_pos.target) {
m_min_target_distance = current_cost;
DEBUG_OUT(LVL " Pathfinder: target found!" << std::endl);
return true;
}
bool retval = false;
// the 4 cardinal directions
const static v3s16 directions[4] = {
v3s16(1,0, 0),
v3s16(-1,0, 0),
v3s16(0,0, 1),
v3s16(0,0,-1)
};
for (v3s16 direction : directions) {
if (direction != srcdir) {
PathCost cost = g_pos.getCost(direction);
if (cost.valid) {
direction.Y = cost.y_change;
v3s16 ipos2 = ipos + direction;
if (!isValidIndex(ipos2)) {
DEBUG_OUT(LVL " Pathfinder: " << PP(ipos2) <<
" out of range, max=" << PP(m_limits.MaxEdge) << std::endl);
continue;
}
PathGridnode &g_pos2 = getIndexElement(ipos2);
if (!g_pos2.valid) {
VERBOSE_TARGET << LVL "Pathfinder: no data for new position: "
<< PP(ipos2) << std::endl;
continue;
}
assert(cost.value > 0);
int new_cost = current_cost + cost.value;
// check if there already is a smaller path
if ((m_min_target_distance > 0) &&
(m_min_target_distance < new_cost)) {
return false;
}
if ((g_pos2.totalcost < 0) ||
(g_pos2.totalcost > new_cost)) {
DEBUG_OUT(LVL "Pathfinder: updating path at: "<<
PP(ipos2) << " from: " << g_pos2.totalcost << " to "<<
new_cost << std::endl);
if (updateAllCosts(ipos2, invert(direction),
new_cost, level)) {
retval = true;
}
}
else {
DEBUG_OUT(LVL "Pathfinder:"
" already found shorter path to: "
<< PP(ipos2) << std::endl);
}
}
else {
DEBUG_OUT(LVL "Pathfinder:"
" not moving to invalid direction: "
<< PP(directions[i]) << std::endl);
}
}
}
return retval;
}
/******************************************************************************/
int Pathfinder::getXZManhattanDist(v3s16 pos)
{
int min_x = MYMIN(pos.X, m_destination.X);
int max_x = MYMAX(pos.X, m_destination.X);
int min_z = MYMIN(pos.Z, m_destination.Z);
int max_z = MYMAX(pos.Z, m_destination.Z);
return (max_x - min_x) + (max_z - min_z);
}
/******************************************************************************/
bool Pathfinder::updateCostHeuristic(v3s16 isource, v3s16 idestination)
{
// A* search algorithm.
// The open list contains the pathfinder nodes that still need to be
// checked. The priority queue sorts the pathfinder nodes by
// estimated cost, with lowest cost on the top.
std::priority_queue<v3s16, std::vector<v3s16>, PathfinderCompareHeuristic>
openList(PathfinderCompareHeuristic(this));
v3s16 source = getRealPos(isource);
v3s16 destination = getRealPos(idestination);
// initial position
openList.push(source);
// the 4 cardinal directions
const static v3s16 directions[4] = {
v3s16(1,0, 0),
v3s16(-1,0, 0),
v3s16(0,0, 1),
v3s16(0,0,-1)
};
v3s16 current_pos;
PathGridnode& s_pos = getIndexElement(isource);
s_pos.source = true;
s_pos.totalcost = 0;
// estimated cost from start to finish
int cur_manhattan = getXZManhattanDist(destination);
s_pos.estimated_cost = cur_manhattan;
while (!openList.empty()) {
// Pick node with lowest total cost estimate.
// The "cheapest" node is always on top.
current_pos = openList.top();
openList.pop();
v3s16 ipos = getIndexPos(current_pos);
// check if node is inside searchdistance and valid
if (!isValidIndex(ipos)) {
DEBUG_OUT(LVL " Pathfinder: " << PP(current_pos) <<
" out of search distance, max=" << PP(m_limits.MaxEdge) << std::endl);
continue;
}
PathGridnode& g_pos = getIndexElement(ipos);
g_pos.is_closed = true;
g_pos.is_open = false;
if (!g_pos.valid) {
continue;
}
if (current_pos == destination) {
// destination found, terminate
g_pos.target = true;
return true;
}
// for this node, check the 4 cardinal directions
for (v3s16 direction_flat : directions) {
int current_totalcost = g_pos.totalcost;
// get cost from current node to currently checked direction
PathCost cost = g_pos.getCost(direction_flat);
if (!cost.updated) {
cost = calcCost(current_pos, direction_flat);
g_pos.setCost(direction_flat, cost);
}
// update Y component of direction if neighbor requires jump or fall
v3s16 direction_3d = v3s16(direction_flat);
direction_3d.Y = cost.y_change;
// get position of true neighbor
v3s16 neighbor = current_pos + direction_3d;
v3s16 ineighbor = getIndexPos(neighbor);
PathGridnode &n_pos = getIndexElement(ineighbor);
if (cost.valid && !n_pos.is_closed && !n_pos.is_open) {
// heuristic function; estimate cost from neighbor to destination
cur_manhattan = getXZManhattanDist(neighbor);
// add neighbor to open list
n_pos.sourcedir = invert(direction_3d);
n_pos.totalcost = current_totalcost + cost.value;
n_pos.estimated_cost = current_totalcost + cost.value + cur_manhattan;
n_pos.is_open = true;
openList.push(neighbor);
}
}
}
// no path found; all possible nodes within searchdistance have been exhausted
return false;
}
/******************************************************************************/
bool Pathfinder::buildPath(std::vector<v3s16> &path, v3s16 ipos)
{
// The cost calculation should have set a source direction for all relevant nodes.
// To build the path, we go backwards from the destination until we reach the start.
for(u32 waypoints = 1; waypoints++; ) {
if (waypoints > PATHFINDER_MAX_WAYPOINTS) {
ERROR_TARGET << "Pathfinder: buildPath: path is too long (too many waypoints), aborting" << std::endl;
return false;
}
// Insert node into path
PathGridnode &g_pos = getIndexElement(ipos);
if (!g_pos.valid) {
ERROR_TARGET << "Pathfinder: buildPath: invalid next pos detected, aborting" << std::endl;
return false;
}
g_pos.is_element = true;
path.push_back(ipos);
if (g_pos.source)
// start node found, terminate
return true;
// go to the node from which the pathfinder came
ipos += g_pos.sourcedir;
}
ERROR_TARGET << "Pathfinder: buildPath: no source node found" << std::endl;
return false;
}
/******************************************************************************/
v3s16 Pathfinder::walkDownwards(v3s16 pos, unsigned int max_down) {
if (max_down == 0)
return pos;
v3s16 testpos = v3s16(pos);
MapNode node_at_pos = m_env->getMap().getNode(testpos);
const NodeDefManager *ndef = m_env->getGameDef()->ndef();
unsigned int down = 0;
while ((node_at_pos.param0 != CONTENT_IGNORE) &&
(!ndef->get(node_at_pos).walkable) &&
(testpos.Y > m_limits.MinEdge.Y) &&
(down <= max_down)) {
testpos += v3s16(0, -1, 0);
down++;
node_at_pos = m_env->getMap().getNode(testpos);
}
//did we find surface?
if ((testpos.Y >= m_limits.MinEdge.Y) &&
(node_at_pos.param0 != CONTENT_IGNORE) &&
(ndef->get(node_at_pos).walkable)) {
if (down == 0) {
pos = testpos;
} else if ((down - 1) <= max_down) {
//difference of y-pos +1 (target node is ABOVE solid node)
testpos += v3s16(0, 1, 0);
pos = testpos;
}
else {
VERBOSE_TARGET << "Pos too far above ground: " <<
"Index: " << PP(getIndexPos(pos)) <<
"Realpos: " << PP(getRealPos(getIndexPos(pos))) << std::endl;
}
} else {
DEBUG_OUT("Pathfinder: no surface found below pos" << std::endl);
}
return pos;
}
#ifdef PATHFINDER_DEBUG
/******************************************************************************/
void Pathfinder::printCost()
{
printCost(DIR_XP);
printCost(DIR_XM);
printCost(DIR_ZP);
printCost(DIR_ZM);
}
/******************************************************************************/
void Pathfinder::printYdir()
{
printYdir(DIR_XP);
printYdir(DIR_XM);
printYdir(DIR_ZP);
printYdir(DIR_ZM);
}
/******************************************************************************/
void Pathfinder::printCost(PathDirections dir)
{
std::cout << "Cost in direction: " << dirToName(dir) << std::endl;
std::cout << std::setfill('-') << std::setw(80) << "-" << std::endl;
std::cout << std::setfill(' ');
for (int y = 0; y < m_max_index_y; y++) {
std::cout << "Level: " << y << std::endl;
std::cout << std::setw(4) << " " << " ";
for (int x = 0; x < m_max_index_x; x++) {
std::cout << std::setw(4) << x;
}
std::cout << std::endl;
for (int z = 0; z < m_max_index_z; z++) {
std::cout << std::setw(4) << z <<": ";
for (int x = 0; x < m_max_index_x; x++) {
if (getIdxElem(x, y, z).directions[dir].valid)
std::cout << std::setw(4)
<< getIdxElem(x, y, z).directions[dir].value;
else
std::cout << std::setw(4) << "-";
}
std::cout << std::endl;
}
std::cout << std::endl;
}
}
/******************************************************************************/
void Pathfinder::printYdir(PathDirections dir)
{
std::cout << "Height difference in direction: " << dirToName(dir) << std::endl;
std::cout << std::setfill('-') << std::setw(80) << "-" << std::endl;
std::cout << std::setfill(' ');
for (int y = 0; y < m_max_index_y; y++) {
std::cout << "Level: " << y << std::endl;
std::cout << std::setw(4) << " " << " ";
for (int x = 0; x < m_max_index_x; x++) {
std::cout << std::setw(4) << x;
}
std::cout << std::endl;
for (int z = 0; z < m_max_index_z; z++) {
std::cout << std::setw(4) << z <<": ";
for (int x = 0; x < m_max_index_x; x++) {
if (getIdxElem(x, y, z).directions[dir].valid)
std::cout << std::setw(4)
<< getIdxElem(x, y, z).directions[dir].y_change;
else
std::cout << std::setw(4) << "-";
}
std::cout << std::endl;
}
std::cout << std::endl;
}
}
/******************************************************************************/
void Pathfinder::printType()
{
std::cout << "Type of node:" << std::endl;
std::cout << std::setfill('-') << std::setw(80) << "-" << std::endl;
std::cout << std::setfill(' ');
for (int y = 0; y < m_max_index_y; y++) {
std::cout << "Level: " << y << std::endl;
std::cout << std::setw(3) << " " << " ";
for (int x = 0; x < m_max_index_x; x++) {
std::cout << std::setw(3) << x;
}
std::cout << std::endl;
for (int z = 0; z < m_max_index_z; z++) {
std::cout << std::setw(3) << z <<": ";
for (int x = 0; x < m_max_index_x; x++) {
char toshow = getIdxElem(x, y, z).type;
std::cout << std::setw(3) << toshow;
}
std::cout << std::endl;
}
std::cout << std::endl;
}
std::cout << std::endl;
}
/******************************************************************************/
void Pathfinder::printPathLen()
{
std::cout << "Pathlen:" << std::endl;
std::cout << std::setfill('-') << std::setw(80) << "-" << std::endl;
std::cout << std::setfill(' ');
for (int y = 0; y < m_max_index_y; y++) {
std::cout << "Level: " << y << std::endl;
std::cout << std::setw(3) << " " << " ";
for (int x = 0; x < m_max_index_x; x++) {
std::cout << std::setw(3) << x;
}
std::cout << std::endl;
for (int z = 0; z < m_max_index_z; z++) {
std::cout << std::setw(3) << z <<": ";
for (int x = 0; x < m_max_index_x; x++) {
std::cout << std::setw(3) << getIdxElem(x, y, z).totalcost;
}
std::cout << std::endl;
}
std::cout << std::endl;
}
std::cout << std::endl;
}
/******************************************************************************/
std::string Pathfinder::dirToName(PathDirections dir)
{
switch (dir) {
case DIR_XP:
return "XP";
break;
case DIR_XM:
return "XM";
break;
case DIR_ZP:
return "ZP";
break;
case DIR_ZM:
return "ZM";
break;
default:
return "UKN";
}
}
/******************************************************************************/
void Pathfinder::printPath(std::vector<v3s16> path)
{
unsigned int current = 0;
for (std::vector<v3s16>::iterator i = path.begin();
i != path.end(); ++i) {
std::cout << std::setw(3) << current << ":" << PP((*i)) << std::endl;
current++;
}
}
#endif
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